Ice cream, ice milk, sherbet compositions and like compositions basically contain milk solids, fat, sugar and water in varying amounts. The fat and water form an emulsion in which the non-fat milk solids and sugar are distributed in colloidal form or dissolved. At the present time, the accepted identification of ice cream, ice milk and sherbet indicates compositions containing butterfat. There are, however, like products on the market in which the butterfat has been replaced by vegetable or animal fat. These equivalent products are included in the scope of the present invention.
The amounts and proportions of the basic constituents in the above products vary widely. Broadly they contain from about 1% to 16% fat, about 6% to 20% non-fat milk solids, about 8% to 18% sugar and about 35% to 85% water all by weight of the total composition. A typical ice cream composition basically contains from about 4% to 16% butterfat, about 6% to 14% non-fat milk solids, about 8% to 18% sugar and about 35% to 45% water all by weight of the total ice cream composition. Ice milk, traditionally contains about 3% to 7% butterfat and from about 14% to 20% non-fat milk solids by weight of the ice milk composition. Sherbets traditionally contain about 1% to 2% fat, about 3% to 5% non-fat milk solids and about 75% to 85% water by weight based upon the total sherbet composition. Hereinafter, the term ice cream shall mean and include ice cream, ice milk, sherbet and equivalent products described above.
Corn syrup solids are frequently added to the mixtures to enhance smoothness and add sweetness and solids to the mixtures. Emulsifiers such as monoglycerides or polysorbates are also frequently added to help maintain the fat in water emulsions. Stabilizers may be added to prevent the water from separating out of the mixture and forming ice and leaving the other ingredients in a dense mass.
Commercially produced products of the above type are generally packaged and put into marketing channels in which they may not remain completely hard frozen at all times. Cyclical storage temperatures of 0.degree. to 40.degree. F. are to be expected in the course of wholesale and retail distribution. Without some means of stabilizing a mixture, the temperature changes cause separation of the water from the other constituents. Such separation is frequently called "wheying out." Wheying out, in turn, causes iciness, chewiness or melting in the mouth which is too fast for good quality products.
Heretofore, carrageenan gum colloids have been incorporated into commercially produced products to prevent separation during processing and storage. The capability of carrageenan gum to stabilize such products has been attributed to an interaction with the milk protein. While carrageenan gum can be used alone, commercially it is generally used in combinations with other gums. At the present carrageenan is used in combination with guar gum, locust bean gum, caboxymethyl cellulose or in combinations thereof. Usually the carrageenan gum makes up from about 1% to 10% by weight of the stabilizers composition. The use of the above stabilizers has the disadvantage of substantially raising the viscosity of the initial product mixture and, thereby, making the actual manufacturing process slower than it could be without the increase in viscosity.
A combination of xanthomonas gum, locust bean gum and guar gum has been mentioned in the art as stabilizers for ice cream. This combination, when evaluated by the inventors, produced ice cream mixes exhibiting viscosities which were only slightly lower than those stabilized with carrageenan gum containing stabilizers. A number of natural gums have been evaluated by the inventors to determine their stabilizing effect upon ice cream. Locust bean gum alone produced a mixture that did not whip. Guar gum produced a curdled mixture. Xanthomonas gum alone produced an icy, chewy mixture.